IB/ehca: Use proper GFP_ flags for get_zeroed_page()

Here is a patch for ehca to use proper flag, ie. GFP_ATOMIC
resp. GFP_KERNEL, when calling get_zeroed_page() to prevent "Bug:
scheduling while atomic...". This error does not cause a kernel panic
but makes ipoib un-usable afterwards. It is reproducible on
2.6.20-rc4 if one does ifconfig down during a flood ping test. I have
not observed this error in earlier releases incl. 2.6.20-rc1.

This error occurs when a qp event/irq is received and ehca event
handler allocates a control block/page to obtain HCA error data block.
Use of GFP_ATOMIC when in interrupt context prevents this issue.

Signed-off-by Hoang-Nam Nguyen <[e-mail]>
Signed-off-by: Roland Dreier <[e-mail]>

drivers/infiniband/hw/ehca/ehca_hca.c

···
 					      ib_device);
 	struct hipz_query_hca *rblock;
 
-	rblock = ehca_alloc_fw_ctrlblock();
+	rblock = ehca_alloc_fw_ctrlblock(GFP_KERNEL);
 	if (!rblock) {
 		ehca_err(&shca->ib_device, "Can't allocate rblock memory.");
 		return -ENOMEM;
···
 					      ib_device);
 	struct hipz_query_port *rblock;
 
-	rblock = ehca_alloc_fw_ctrlblock();
+	rblock = ehca_alloc_fw_ctrlblock(GFP_KERNEL);
 	if (!rblock) {
 		ehca_err(&shca->ib_device, "Can't allocate rblock memory.");
 		return -ENOMEM;
···
 		return -EINVAL;
 	}
 
-	rblock = ehca_alloc_fw_ctrlblock();
+	rblock = ehca_alloc_fw_ctrlblock(GFP_KERNEL);
 	if (!rblock) {
 		ehca_err(&shca->ib_device,  "Can't allocate rblock memory.");
 		return -ENOMEM;
···
 		return -EINVAL;
 	}
 
-	rblock = ehca_alloc_fw_ctrlblock();
+	rblock = ehca_alloc_fw_ctrlblock(GFP_KERNEL);
 	if (!rblock) {
 		ehca_err(&shca->ib_device, "Can't allocate rblock memory.");
 		return -ENOMEM;

drivers/infiniband/hw/ehca/ehca_irq.c

···
 	u64 *rblock;
 	unsigned long block_count;
 
-	rblock = ehca_alloc_fw_ctrlblock();
+	rblock = ehca_alloc_fw_ctrlblock(GFP_ATOMIC);
 	if (!rblock) {
 		ehca_err(&shca->ib_device, "Cannot allocate rblock memory.");
 		ret = -ENOMEM;

drivers/infiniband/hw/ehca/ehca_iverbs.h

···
 int ehca_munmap(unsigned long addr, size_t len);
 
 #ifdef CONFIG_PPC_64K_PAGES
-void *ehca_alloc_fw_ctrlblock(void);
+void *ehca_alloc_fw_ctrlblock(gfp_t flags);
 void ehca_free_fw_ctrlblock(void *ptr);
 #else
-#define ehca_alloc_fw_ctrlblock() ((void *) get_zeroed_page(GFP_KERNEL))
+#define ehca_alloc_fw_ctrlblock(flags) ((void *) get_zeroed_page(flags))
 #define ehca_free_fw_ctrlblock(ptr) free_page((unsigned long)(ptr))
 #endif
 

drivers/infiniband/hw/ehca/ehca_main.c

···
 #ifdef CONFIG_PPC_64K_PAGES
 static struct kmem_cache *ctblk_cache = NULL;
 
-void *ehca_alloc_fw_ctrlblock(void)
+void *ehca_alloc_fw_ctrlblock(gfp_t flags)
 {
-	void *ret = kmem_cache_zalloc(ctblk_cache, GFP_KERNEL);
+	void *ret = kmem_cache_zalloc(ctblk_cache, flags);
 	if (!ret)
 		ehca_gen_err("Out of memory for ctblk");
 	return ret;
···
 	u64 h_ret;
 	struct hipz_query_hca *rblock;
 
-	rblock = ehca_alloc_fw_ctrlblock();
+	rblock = ehca_alloc_fw_ctrlblock(GFP_KERNEL);
 	if (!rblock) {
 		ehca_gen_err("Cannot allocate rblock memory.");
 		return -ENOMEM;
···
 	int ret = 0;
 	struct hipz_query_hca *rblock;
 
-	rblock = ehca_alloc_fw_ctrlblock();
+	rblock = ehca_alloc_fw_ctrlblock(GFP_KERNEL);
 	if (!rblock) {
 		ehca_err(&shca->ib_device, "Can't allocate rblock memory.");
 		return -ENOMEM;
···
 									   \
 	shca = dev->driver_data;					   \
 									   \
-	rblock = ehca_alloc_fw_ctrlblock();				   \
+	rblock = ehca_alloc_fw_ctrlblock(GFP_KERNEL);			   \
 	if (!rblock) {						           \
 		dev_err(dev, "Can't allocate rblock memory.");		   \
 		return 0;						   \

drivers/infiniband/hw/ehca/ehca_mrmw.c

···
 	u32 i;
 	u64 *kpage;
 
-	kpage = ehca_alloc_fw_ctrlblock();
+	kpage = ehca_alloc_fw_ctrlblock(GFP_KERNEL);
 	if (!kpage) {
 		ehca_err(&shca->ib_device, "kpage alloc failed");
 		ret = -ENOMEM;
···
 	ehca_mrmw_map_acl(acl, &hipz_acl);
 	ehca_mrmw_set_pgsize_hipz_acl(&hipz_acl);
 
-	kpage = ehca_alloc_fw_ctrlblock();
+	kpage = ehca_alloc_fw_ctrlblock(GFP_KERNEL);
 	if (!kpage) {
 		ehca_err(&shca->ib_device, "kpage alloc failed");
 		ret = -ENOMEM;

drivers/infiniband/hw/ehca/ehca_qp.c

···
 	unsigned long spl_flags = 0;
 
 	/* do query_qp to obtain current attr values */
-	mqpcb = ehca_alloc_fw_ctrlblock();
+	mqpcb = ehca_alloc_fw_ctrlblock(GFP_KERNEL);
 	if (!mqpcb) {
 		ehca_err(ibqp->device, "Could not get zeroed page for mqpcb "
 			 "ehca_qp=%p qp_num=%x ", my_qp, ibqp->qp_num);
···
 		return -EINVAL;
 	}
 
-	qpcb = ehca_alloc_fw_ctrlblock();
+	qpcb = ehca_alloc_fw_ctrlblock(GFP_KERNEL);
 	if (!qpcb) {
 		ehca_err(qp->device,"Out of memory for qpcb "
 			 "ehca_qp=%p qp_num=%x", my_qp, qp->qp_num);